Embodiments herein generally relate to media paths within devices that use nip rollers to move sheets or webs of media, and more particularly to a pivoting nip structure that can be used, for example, in the area where an opening panel exists to keep proper pressure on the media within the nip.
Most multi-function printers/multi-function devices (MFPs/MFDs) and related imaging devices, sometimes simply referred to as “printers” herein, use roller nips to move media throughout the machine. Typically, a nip uses a driven shaft with multiple rollers opposed by complementary idler rollers. The idler rollers are typically spring loaded to provide the nip load. The driven nip roller shaft is typically stationary due to drive system connections. Spring loaded idlers allow for tolerance variations in roller diameters and shaft placement and provide the nip clamping force so paper is fed without slippage. An issue occurs when one side of a “subsequent” transport roller set is mounted in the printer media feed path and the other to a panel or door that moves somehow (e.g., opens to an exterior sheet feeder). As media feed transfers from the pick roller to the subsequent roller set, the paper can become taut, exerting normal force against the door mounted idler rollers, which in turn causes the nip clamping force to be reduced or eliminated as the nip “opens”. The nip opening does not need to be a fully open condition, the term “open” here indicates any nip gap that would cause a loss of traction. The result is poor feeding or a loss of feed motion. In the worst case, the customer experiences a paper jam.